/Engine/Source/Runtime/Engine/Public/MaterialCompiler.h
int32 VirtualTextureParameter ( [FName](API\Runtime\Core\UObject\FName) ParameterName, [URuntimeVirtualTexture](API\Runtime\Engine\VT\URuntimeVirtualTexture) * DefaultValue, int32 TextureLayerIndex, int32 PageTableLayerIndex, int32 & TextureReferenceIndex, EMaterialSamplerType SamplerType )